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More than halfway across the universe, an enormous blue star nicknamed Icarus is the farthest individual star ever seen. Normally, it would be much too faint to view, even with the world’s largest telescopes. But through a quirk of nature that tremendously amplifies the star’s feeble glow, astronomers using NASA’s Hubble Space Telescope were able to pinpoint this faraway star and set a new distance record. They also used Icarus to test one theory of dark matter, and to probe the make-up of a foreground galaxy cluster.

Astronomers using the NASA/ESA Hubble Space Telescope have found the most distant star ever discovered. The hot blue star existed only 4.4 billion years after the Big Bang. This discovery provides new insight into the formation and evolution of stars in the early Universe, the constituents of galaxy clusters and also on the nature of dark matter.

A colourful design capturing the essence of ESA's CHEOPS mission, which will measure the size of planets as they cross in front of their parent stars, has been selected for the rocket carrying the satellite into space.

NASA is investing in technology concepts that includes meteoroid impact detection, space telescope swarms and small orbital debris mapping technologies that may one day be used for future space exploration missions.

An X-ray telescope is characterized by four parameters: angular resolution, effective area, mass, and production cost. Researchers at NASA GSFC have developed a new X-ray mirror technology that is expected to improve one or more of these parameters by at least an order of magnitude, compared to the mirrors currently employed on missions such as the Chandra X-ray Observatory and the Nuclear Spectroscopic Telescope Array (NuSTAR).

A Wolter-I mirror segment with a thickness of 0.6 mm. This mirror has a dimension of approximately 100 mm by 100 mm. Tens of thousands of mirror segments like this one will be aligned and integrated to make an assembly to achieve several m2 of effective area. (Credit: Bill Hrybyk)

This mirror technology combines a polishing process used for fabricating optics of the highest quality with use of monocrystalline silicon—a material used in the semiconductor industry. Monocrystalline silicon is free of internal stress and thereby enables development of extremely thin (less than 1 mm) and lightweight (areal density less than 2.5 kg/m2) mirrors. The GSFC team has been working to perfect this technology since 2011, and in 2016 they developed a process to make Wolter-I (parabolic or hyperbolic) mirrors as thin as 0.5 mm with figure quality better than 3 arcsec—a tenfold improvement over the NuSTAR mirrors. In parallel, the team developed a bonding process that preserves the figure and alignment of these thin mirrors, while enabling them to sustain a typical space launch vibration environment.

Impact

This mirror technology will enable observation and study of supermassive black holes, galaxy clusters, and the centers of nearby galaxies, where myriad stellar binaries containing compact objects such as neutron stars and black holes reside. This monocrystalline silicon mirror technology has the potential to enable a quantum jump in capability with a mass and production cost comparable to today’s technology. The modular nature of this mirror technology, where a large mirror assembly is constructed of many small mirror segments, makes it highly amenable to parallel and mass production, both of which are essential for meeting schedule and cost requirements of future missions. Likewise, this technology is also suitable for making mirror assemblies for missions of all sizes.

Status and Future Plans

The team will refine the mirror fabrication and bonding processes to improve the figure quality by at least an order of magnitude in the next five to ten years, so the technology will be ready to implement on a major X-ray observatory in the 2020s.

Sponsoring Organization

SMD’s Astrophysics Division supports this development effort via the APRA and SAT programs, and William Zhang at GSFC is the PI.